Abstract math, sets and logic proof

beatka6
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Homework Statement


If A is a set that contains a finite number of elements, we say A is a finite set. If
A is a finite set, we write |A| to denote the number of elements in the set A. We
also write |B| < ∞ to indicate that B is a finite set. Denote the sets X and Y by
X = {T : T is a proper subset of P(Z) or |T| < ∞}; Y = {T element of X : T≠ ∅}
Prove or disprove the following:
(there exist X element of R)(∅ element of R and ( for all S element of Y)(|R|≤ |S|}


Homework Equations




The Attempt at a Solution


I think that statement is true because of or in the statement, but I have no idea how to prove it
 
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I can't understand what it is that you are trying to show. Can you write it out in words?
 
It s number 5 from the attachment.
 

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There are two things I don't understand about this problem. First, when finding the nth root of a number, there should in theory be n solutions. However, the formula produces n+1 roots. Here is how. The first root is simply ##\left(r\right)^{\left(\frac{1}{n}\right)}##. Then you multiply this first root by n additional expressions given by the formula, as you go through k=0,1,...n-1. So you end up with n+1 roots, which cannot be correct. Let me illustrate what I mean. For this...
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